Can Human Lice Be Transmitted to Rats?

Human lice, known as obligate blood feeders, require human blood to grow, mature and produce eggs. They cannot be transmitted to rodents because they cannot feed on rat blood. If separated from human hosts, they dehydrate quickly and die.

Different Types of Lice

• Depending on where they survive on the body, there are three types of human lice: Pthirus pubis ("crab louse," pubic area); Pediculus humanus corporis (body louse); and Pediculus humanus capitis (head louse). A different kind of lice affects rats. Known as Polyplax spinulosa, rat lice are transmitted via infested nests or direct contact.

Transmission Limitations

• Lice infestations occur due to close contact between people. Unable to jump or fly, lice crawl. In order to transmit a human louse to a rat, the rat must be next to or on the infested area of the human body. Even if this improbable transmission occurs, the human louse is unable to survive on a rat host.

Lice and Disease

• Human body lice can spread epidemic typhus, a severe form of typhus caused by the bacteria Rickettsia prowazekii. Although epidemic typhus is rare in the United States, it occurs in areas with substandard hygiene and crowded housing. A milder form of the disease, murine typhus, can be spread by lice on rodents.